LizardTech® recently released version 8 of GeoExpress® software at GEOINT 2010 Symposium in New Orleans. The image manipulation and compression software now supports alpha bands for true transparency control, and multispectral imagery for a much expanded range of band selection. Composite mosaicking has also been improved for GeoExpress 8.

To support these features, GeoExpress introduces the ability to encode raster imagery to the latest version of the industry standard MrSID® format, MrSID Generation 4 (MG4™). Files encoded to the MG4 format can be viewed in either of LizardTech's free viewers, ExpressView™ Browser Plug-in and the standalone GeoViewer application.

The geospatial world has for some time chafed against the confines of three-banded imagery. Lately there has been increasing use of multispectral imagery -- let's call that more than three bands, for example RGB + infrared (RGBIR) – and even hyperspectral imagery – say, more than fifty or a hundred bands – and users want to be able to take full advantage of all those channels. GeoExpress 8 supports outputting images with up to 255 bands.

The MG4 format's support for alpha bands means that users can more accurately control the opacity or transparency of image data, which is particularly useful in creating mosaics. You can specify that all data be opaque, or you can have GeoExpress query the image metadata to find out what the value should be and use that value to create an alpha mask, or you can specify a transparency color value of your choosing. With alpha band support, you have greater control over how your image mosaics look.

And speaking of mosaics, it used to be that composite mosaics, which include whole MrSID files wrapped in a container, were quick to view but took a long time to create. MG4 composite mosaics give you the speed advantage at both ends. A new LizardTech technology creates the composite quickly and includes an overview, which is used by decoding applications for instant viewing. The advantage of composites – easy updating – is now more compelling than ever.